Right now, I’m cruising at 35,000 feet on a Delta flight surfing the Web with Gogo’s Inflight internet access. My flight has been delayed, and I want to tell my wife that she can pick me up later. And it occurred to me: I wonder if Google’s new “Call from Gmail” feature would work while flying.

Sure enough, I opened Gmail’s “Google Talk Plugin” interface, entered Gadling editor Grant Martin’s phone number and pressed “call.” As it turned out, he answered the phone — and he could hear me.

What does this mean? Well, it means that, if you’re in-flight, and you have a headset and a Gmail account (and a Gogo Internet pass), you can make free calls from the air (to the US and Canada only) to landlines. This is not new for VOIP (Skype’s infrastructure allows this, though it’s hit and miss), but this is a first for Google.

Is it a win for airline passengers? We’re undecided at this point. While the convenience is certainly nice, do we really need to hear the girl next to us on the plane cooing to her boyfriend via her Gmail account?